import java.util.*;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
/*
 class ListNode {
   int val;
   ListNode next = null;
   public ListNode(int val) {
    this.val = val;
   }
 }
 class Solution {
    public ListNode reverseBetween (ListNode head, int m, int n) {
        // write code here
        //res 用于保存最终结果
        ListNode res = new ListNode(-1);
        ListNode tail = res;
        ListNode p = head;
        for (int i = 1; i < m; i++) {
            ListNode tmp = p.next;
            tail.next = p;
            tail = p;
            p.next = null;
            p = tmp;
        }
        ListNode s = null;
        for (int j = m; j <= n; j++) {
            ListNode tmp = p.next;
            p.next = s;
            s = p;
            p = tmp;
        }
        tail.next = s;
        ListNode cur=s;
        while(cur.next!=null){
            cur=cur.next;
        }
        if (p != null) {
            cur.next = p;
        }
        return res.next;
    }
}*/
/*

import java.util.*;
class ListNode {
    int val;
     ListNode next;
     ListNode(int x) {
         val = x;
         next = null;
     }
 }
*/
/*
import  java.util.*;
class ListNode {
    int val;
    ListNode next;
    ListNode(int x) {
        val = x;
        next = null;
    }
}*/
/*
 class Solution {
    //合并K个有序链表的方法
    public ListNode mergeKLists(ArrayList<ListNode> lists) {
        return mergeList(lists,0,lists.size()-1);
    }
    public ListNode mergeList(ArrayList<ListNode> lists,int left,int right){
        if(left==right) return lists.get(left);
        if(left>right) return null;
        int mid=(left+right)/2;
        ListNode lefttree = mergeList(lists,left,mid);
        ListNode righttree = mergeList(lists,mid+1,right);
        return merge(lefttree,righttree);
    }
    //合并两个有序链表（和力扣的21题一样）
    public ListNode merge(ListNode pHead1,ListNode pHead2){
        ListNode newHead = new ListNode(-1);
        ListNode tail = newHead;
        while(pHead1!=null&&pHead2!=null){
            if(pHead1.val<pHead2.val){
                tail.next = pHead1;
                pHead1=pHead1.next;
                tail=tail.next;
            }else{
                tail.next = pHead2;
                pHead2=pHead2.next;
                tail=tail.next;
            }
        }
        if(pHead1==null){
            tail.next=pHead2;
        }
        if(pHead2==null){
            tail.next=pHead1;
        }
        return newHead.next;
    }
}
*/

/*
 * public class ListNode {
 *   int val;
 *   ListNode next = null;
 *   public ListNode(int val) {
 *     this.val = val;
 *   }
 * }
 */

/* class Solution {

    public ListNode mergeKLists (ArrayList<ListNode> lists) {
        // write code here
        PriorityQueue<ListNode> heap = new PriorityQueue<>(new ListNodeComparator());
        for(ListNode list : lists) {
            while(list != null) {
                heap.add(list);
                list = list.next;
            }
        }
        ListNode head = heap.poll();
        ListNode tail = head;
        while(!heap.isEmpty()) {
            ListNode cur = heap.poll();
            tail.next = cur;
            tail = cur;
            if(heap.isEmpty()) {
                tail.next = null;
            }
        }
        return head;
    }

    class ListNodeComparator implements Comparator<ListNode> {
        @Override
        public int compare(ListNode o1,ListNode o2) {
            return o1.val - o2.val;
        }
    }
}*/



public class Test {
   class Main {
        public static void main(String[] args) {
            Scanner in = new Scanner(System.in);
            int n = in.nextInt();
            List<List<Integer>>list = new ArrayList<>();
            List<Integer>list1 =new ArrayList<>();
            list1.add(1);
            list.add(list1);
            int[][] ret = new int[n][2*n-1];
            for(int i = 0; i<n; i++){
                ret[i][0] = 1;
                ret[i][2*i] = 1;
            }
            for(int i = 1; i<n; i++){
                List<Integer>list2 =new ArrayList<>();
                list2.add(1);
                for(int j = 1;j<2*i+1;j++){
                    if(j==1){
                        List<Integer>list3 = list.get(i-1);
                        int x = list3.get(j)+list3.get(j-1);
                        list2.add(x);
                    }else{
                        List<Integer>list3 = list.get(i-1);
                        int x = list3.get(j)+list3.get(j-1)+list3.get(j-2);
                        list2.add(x);
                    }
                }
                list2.add(1);
                list.add(list2);
            }
            List<Integer>res =list.get(n-1);
            for(int j = 0; j<res.size();j++){
                if(res.get(j)%2==0){
                    System.out.println(j+1);
                    return ;
                }
            }
            System.out.println(-1);
        }
    }
}

























